Concept explainers
Following gastrulation, the cells that have folded inward develop into
- a. endoderm.
- b. mesoderm.
- c. ectoderm.
- d. All of the above are correct.

Introduction:
Gastrulation is a period in the development of an embryo of animals, in which a single layered blastula folds itself in such a way that it forms a cup shaped structure called gastrula. Gastrula further contains two or three layers of tissue. It includes the endoderm, ectoderm and mesoderm.
Answer to Problem 1MCQ
Correct answer:
The cells that have folded inward develop into endoderm, after gone through the gastrulation phase. Therefore, option (a) is correct.
Explanation of Solution
Reason for the correct statement:
The blastula rearranges itself to develop the gastrula, following gastrulation the cells that fold inward develop into the endoderm. Endoderm is the inner most layer which contributes to the development of an embryo
Option (a) is given as “endoderm”.
As, “endoderm is the inner most layer which is formed by the folding of cells after gastrulation phase. Endoderm is the primary germ layer which contributes to the development of an embryo in early stage”, it is the right answer.
Hence, option (a) is correct.
Reasons for the incorrect statements:
Option (b), is given as “mesoderm”.
Mesoderm is the middle layer formed between ectoderm and endoderm. This is the third primary germ layer which also contributes to the development of an embryo. Mesoderm is formed by the interaction of two germ layers including ectoderm and endoderm. Hence, it is a wrong answer.
Option (c), is given as “ectoderm”.
Ectoderm is the outermost germ layer that also forms during the development of an embryo. It covers the outside of the embryo. Hence, it is a wrong answer.
Option (d), is given as “all of the above are correct”.
Endoderm, ectoderm and mesoderm all are the primary germ layers which are formed during the development of an embryo. Ectoderm is the outer layer of tissue and mesoderm is the inner layer of tissue. The cells that have folded inward result in the formation of endoderm. Hence, it is a wrong answer.
Hence, options (b), (c), and (d) are incorrect.
Endoderm is formed by the inward folding of cells followed after gastrulation. Endoderm is the primary germ layer which contributes to the development of an embryo in the early stage.
Want to see more full solutions like this?
Chapter 21 Solutions
BIOL:CONCEPT+INVEST.ETEXT
Additional Science Textbook Solutions
Biological Science (6th Edition)
Applications and Investigations in Earth Science (9th Edition)
Genetics: From Genes to Genomes
Campbell Essential Biology (7th Edition)
HUMAN ANATOMY
Biology: Life on Earth with Physiology (11th Edition)
- Older adults have unique challenges in terms of their nutrient needs and physiological changes. Some changes may make it difficult to consume a healthful diet, so it is important to identify strategies to help overcome these obstacles. From the list below, choose all the correct statements about changes in older adults. Select all that apply. Poor vision can make it difficult for older adults to get to a supermarket, and to prepare meals. With age, taste and visual perception decline. As people age, salivary production increases. In older adults with dysphagia, foods like creamy soups, applesauce, and yogurt are usually well tolerated. Lean body mass increases in older adults.arrow_forwardWhen physical activity increases, energy requirements increase also. Depending on the type, intensity, and duration of physical activity, the body’s requirements for certain macronutrients may change as well. From the list below, choose all the correct statements about the effects of increased physical activity or athletic training. Select all that apply. An athlete who weighs 70 kg (154 lb) should consume 420 to 700 g of carbohydrate per day. How much additional energy an athlete needs depends on the specific activity the athlete engages in and the frequency of the activity. Those participating in vigorous exercise should restrict their fat intake to less than 15%% of total energy intake. Athletes who are following energy-restricted diets are at risk for consuming insufficient protein. The recommendation to limit saturated fat intake to less than 10%% of total energy intake does not apply to athletes or those who regularly engage in vigorous physical activity.arrow_forwardWhen taking vitamins and vitamin-mineral supplements, how can one be sure they are getting what they are taking?arrow_forward
- How many milligrams of zinc did you consume on average per day over the 3 days? (See the Actual Intakes vs. Recommended Intakes Report with all days checked.) Enter the number of milligrams of zinc rounded to the first decimal place in the box below. ______ mg ?arrow_forwardthe direct output from molecular replacement is a coordinate file showing the orientation of the unknown target protein in the unit cell. true or false?arrow_forwardthe direct output from molecular replacement is a coordinate file showing the orientation of the unknown target protein in the unit cell. true or false?arrow_forward
- Did your intake of vitamin C meet or come very close to the recommended amount? yes noarrow_forwardWhich of the following statements about hydration is true? Absence of thirst is a reliable indication that an individual is adequately hydrated. All of these statements are true. Although a popular way to monitor hydration status, weighing yourself before and after intensive physical activity is not a reliable method to monitor hydration. Urine that is the color of apple juice indicates dehydration. I don't know yetarrow_forwardThree of the many recessive mutations in Drosophila melanogaster that affect body color, wing shape, or bristle morphology are black (b) body versus grey in wild type, dumpy (dp), obliquely truncated wings versus long wings in the male, and hooked (hk) bristles versus not hooked in the wild type. From a cross of a dumpy female with a black and hooked male, all of the F1 were wild type for all three of the characters. The testcross of an F1 female with a dumpy, black, hooked male gave the following results: Trait Number of individuals Wild type 169 Black 19 Black, hooked 301 Dumpy, hooked 21 Hooked, dumpy, black 172 Dumpy, black 6 Dumpy 305 Hooked 8 Determine the order of the genes and the mapping distance between genes. Determine the coefficient of confidence for the portion of the chromosome involved in the cross. How much interference takes place in the cross?arrow_forward
- What happens to a microbes membrane at colder temperature?arrow_forwardGenes at loci f, m, and w are linked, but their order is unknown. The F1 heterozygotes from a cross of FFMMWW x ffmmww are test crossed. The most frequent phenotypes in the test cross progeny will be FMW and fmw regardless of what the gene order turns out to be. What classes of testcross progeny (phenotypes) would be least frequent if locus m is in the middle? What classes would be least frequent if locus f is in the middle? What classes would be least frequent if locus w is in the middle?arrow_forward1. In the following illustration of a phospholipid... (Chemistry Primer and Video 2-2, 2-3 and 2-5) a. Label which chains contain saturated fatty acids and non-saturated fatty acids. b. Label all the areas where the following bonds could form with other molecules which are not shown. i. Hydrogen bonds ii. Ionic Bonds iii. Hydrophobic Interactions 12-6 HICIH HICIH HICHH HICHH HICIH OHHHHHHHHHHHHHHHHH C-C-C-C-C-c-c-c-c-c-c-c-c-c-c-c-C-C-H HH H H H H H H H H H H H H H H H H H HO H-C-O H-C-O- O O-P-O-C-H H T HICIH HICIH HICIH HICIH HHHHHHH HICIH HICIH HICIH 0=C HIC -C-C-C-C-C-C-C-C-CC-C-C-C-C-C-C-C-C-H HHHHHHHHH IIIIIIII HHHHHHHH (e-osbiv)arrow_forward
- Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax CollegeBiology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning
- Biology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage LearningBiology: The Unity and Diversity of Life (MindTap...BiologyISBN:9781305073951Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa StarrPublisher:Cengage LearningHuman Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning





