Why are chromosomes not always visible?

a.

They are often very loosely coiled in strands of chromatin

b.

They are wound very tightly

c.

They lose pigment in sunlight

d.

They are often behind the nuclear envelope

The bacteria in some foods are sterilized by placing the food near a source of ionizing radiation does that mean that the food becomes radioactive?

Streptomyces A. resemble fungi in their pattern of growth. B. produce a number of antibiotics. C. produce a characteristic blue green pigment. D. form endospores. E. resemble fungi in their pattern of growth AND produce a number of antibiotics.

Why are gingko trees often planted in urban areas?

If a tall stem is a dominant characteristic, in which case is the characteristic of tall definitely expressed? A. when both alleles contain instructions for tall B. when at least one allele contains instructions for tall C.

The maintenance of boundaries between the internal organs of the body and the outside world is achieved by the endocrine system. 1. True2. False

Which of these substances could be driven across a membrane by the resting membrane potential?

Norway rats have 42 chromosomes in their diploid cells. If a diploid rat cell enters meiosis, how many chromosomes and double-helical molecules of DNA will be present in each daughter cell at the end of meiosis II?

Which discovery is attributed to Phoebus Levene? A. extraction and observation of DNA B. identification of ribose and deoxyribose C. recognition of RNA as DNA's messenger D. construction of an accurate DNA model

A small population of chimpanzees lives in a habitat that undergoes no changes for a long period. how will genetic drift probably affect this population?

Which type of cells can differentiate into many different types of cells? select all that apply