Question

Biology

1. What is the correct order (from small to large)?

1. cells, organelles, organ system, community, ecosystems
2. molecules, organism, population, communities, biosphere
3. molecules, cells, tissues, ecosystems, communities
4. organelles, cells, population, biosphere, ecosystems
5. cells, organs, population, ecosystems, communities

2. All of the gray squirrels that inhabit an oak forest describes a/an:

1. ecosystem
2. biosphere
3. community
4. population
5. colony

3. An atom of oxygen has an atomic number of 8. How many electrons are in the first, second, and third electron shells, respectively?

1. 2, 3, 3
2. 2, 6, 0
3. 8, 0, 0
4. 0, 4, 4
5. none of the above

4. All lipids

1. are made from glycerol and fatty acids.
2. contain nitrogen.
3. have low energy content.
4. are acidic when mixed with water.
5. do not dissolve well in water.

5. Which is not a function of proteins?

1. help make up membranes
2. carry the code for translation from the nucleus
   to the ribosome
3. bind to hormones (hormone receptor)
4. can be hormones
5. speed chemical reactions

6. Which cellular structure is common to all three domains of life?

1. nucleus
2. endoplasmic reticulum
3. mitochondria
4. phospholipid bilayer cell membrane
5. endocytotic vesicles

7. Which of the following best describes the structure of a biological membrane?

1. two layers of phospholipids with proteins embedded between the two layers
2. a mixture of covalently linked phospholipids and proteins that determines which solutes can cross the membrane and which cannot
3. two layers of phospholipids with proteins either spanning
   the layers or on the surface of the layers
4. a fluid structure in which phospholipids and proteins move freely between sides of the membrane
5. two layers of phospholipids (with opposite orientations of the phospholipids in each layer) with each layer covered on the outside with proteins

8. Cells (e.g., bacteria) are taken up by other cells (e.g., an immune cell) by which of the following?

1. pinocytosis
2. exocytosis
3. receptor-mediated endocytosis
4. phagocytosis
5. facilitated diffusion

9. Cellular respiration can best be described as

1. using energy released from breaking high-energy covalent bonds in organic molecules to force ATP formation from ADP and phosphate.
2. taking electrons from food and giving them to
   phosphate to make ATP.
3. taking electrons from food and giving them to
   oxygen to make water and using the energy
   released to drive ATP formation.
4. converting higher-energy organic molecules to lower-energy organic molecules and using the energy
   released to drive ATP formation.

10. Which of the following statements about glycolysis is true?

1. It splits water.
2. It produces FADH₂.
3. It occurs in the cytoplasm.
4. It makes the most ATP
   compared to the two
   other steps.
5. It splits lipids.

11. How many chromosomes are in the middle cell?

1. 1
2. 2
3. 4
4. 8

12. Although the chromosome begins M phase looking as shown below, when is it split?

1. prophase
2. prometaphase
3. metaphase
4. anaphase
5. telophase

13. Which of the following transmits genes from both parents to child, or from one generation of a family to another?

1. DNA
2. gametes
3. somatic cells
4. mitosis
5. nucleotides

14. Privet shrubs and humans each have a diploid number of 46 chromosomes per cell. Why are the two species so dissimilar?

1. Privet chromosomes undergo only mitosis.
2. Privet chromosomes are shaped differently.
3. Human chromosomes have genes grouped
   together differently.
4. The two species have appreciably different
   genes.
5. Privets do not have sex chromosomes.

15. Crossing over begins to occur during

1. anaphase I
2. anaphase II
3. prophase I
4. metaphase II
5. telophase II

16. In this cell, what phase is represented?

1. mitotic metaphase
2. meiosis I anaphase
3. meiosis I metaphase
4. meiosis II anaphase
5. meiosis II metaphase

17. Pea plants were particularly well suited for use in Mendel’s breeding experiments for all of the following reasons except that

1. peas show easily observed variations in a number of characters, such as pea shape and flower color.
2. it is possible to control matings between different pea plants.
3. it is possible to obtain large numbers of progeny from any given cross.
4. peas have an unusually long generation time.
5. many of the observable characters that vary in pea plants are controlled by single genes.

18. A cross between homozygous purple-flowered and homozygous white-flowered pea plants results in offspring with purple flowers. This demonstrates

1. the blending model of genetics.
2. true breeding.
3. dominance.
4. a dihybrid cross.
5. the mistakes made by Mendel.

Help, please

Answer 1

Answer 1- B) molecules, organism, population, communities, biosphere

Reason- a population is a group of organisms of the same species living in a given area. A community is all species living and interacting in a given area. Biosphere is the region of atmosphere of the earth occupied by living organisms.

Answer 2- D) population

Reason- All of the gray squirrels that inhabit an oak forest describes a population as it is the group of organisms of the same species living in a particular area.

Answer 3- B) 2,6,0

Reason- the maximum number of electrons occupied by first shell can be 2 only and by second shell is 8.

Therefore, for oxygen with atomic number 8, electronic configuration will be 2,6,0.

Answer 4- D) do not dissolve well in water

Reason- Lipids are nonpolar molecules and water is polar i.e lipids and water molecules do not bond or share electrons. Thus lipids are not soluble in water.