CSIR NET Life science 2013 Exam - Practice Questions

1. Corals reproduce by forming multicellular outgrowths from the body wall that detach and develop into independent organisms. Which statement most closely describes this form of reproduction in another organism?

• Molds reproduce by sporulation.
• Hydras reproduce by budding.
• Paramecia reproduce by binary fission.
• Maple trees reproduce by seed formation.

2. Which reproductive process is correctly paired with the structure in which it occurs?

• meiosis: oviduct
• fertilization: gonad
• gametogenesis: testis
• pollination: antheridium

3. A McIntosh apple tree brand was grafted to an Ida Red apple tree. The fruit produced by the newly grafted piece will be

• Ida Red apples only
• McIntosh apples only
• 50 % McIntosh and 50% Ida Red
• apples that are a composite of both McIntosh and Ida Red varieties

4. Why is the release of 2000 to 10000 eggs by a female salmon during one season considered a favorable reproductive adaptation?

• External fertilization increases the chance of sperm reaching the eggs.
• Overproduction increases the rate of embryo development.
• The species is declining, so the reproductive rate has increased to respond to that.
• Unfavorable environmental conditions may destroy gametes.

5. Animals that produce embryos that are born small and relatively immature and must complete their development in a pouch are known as

• marsupials
• monotremes
• placental mammals
• nonplacental mammals

6. The brightly colored, highly scented flowers on a rosebush are an adaptation for

• wind pollenation
• insect pollination
• spore production
• embryo nutrition

7. Using the results of his experiments with pea plant crosses, Mendel discovered

• the principles of dominance, segregation and inedpendent assortment
• that pea plants develop mutations after exposure to radiation
• intermediate inheritence and gene linkage
• that DNA is involved in the inheritence of dominant traits

8. In a certain variety of chicken, the genes for black feather color and the genes for white feather color are codominant. This variety of chicken will most likely have

• three possible phenotypes for feather color
• white feather color
• black feather color
• only two genotypes for feather color

9. In fruit flies red eye color (R) is dominant and white eye color (r) is recessive. The allele for eye color is carried on the X chromosome. Which cross would most likely produce 50% white-eyed males and 50% red-eyed males?

• X^RX^R x X^RY
• X^RX^R x X^rY
• X^RX^r x X^rY
• X^rX^r x X^RY

10. A mutation may be passed on to future generations if it occurs within specialized cells of the

• ovary
• brain
• heart
• liver#

Answer
1. Hydras reproduce by budding.
2. gametogenesis: testis
3. McIntosh apples only
4. Unfavorable environmental conditions may destroy gametes.
5. marsupials
6. insect pollination
7. the principles of dominance, segregation and inedpendent assortment
8. three possible phenotypes for feather color
9. XRXR x XRY
10. ovary