39
Reproductive cells are haploid (have 1/2 the chromosomes), whereas somatic/body cells are diploid (have the full set of chromosomes)
This makes sense if you think about it. Using the example from the question, every dog has 78 chromosomes. This includes two of each (there are two chromosome 1's, two chromosome 2's, etc. This is visible in the karyotype attached). One set of these chromosomes were inherited from the mother, and one set from the father. Each parent contributed 39 chromosomes (one chromosome 1, one chromosome 2, etc.). If the dog in the question were to have 78 chromosomes in its sperm cells, it would contribute two sets to its offspring. When combined with the chromosomes in the egg cell, the offspring would end up with extra chromosomes. Therefore, both the sperm and the egg cells will have 39 chromosomes, one of each. When combined, they will produce offspring with 78 chromosomes, the proper number.
A decrease in dissolved oxygen.
This is because oxygen is a byproduct of photosynthesis. If the plants are in water, some of the oxygen they produce will become dissolved in it. Without those plants, you have less dissolved oxygen.
Answer:
The somatic cells of fruit flies contain eight chromosomes, which means they have two sets of four chromosomes. Meiosis is the process by which sex cells are produced. Sex cells are haploid, which means they have one set of chromosomes.
Explanation:
Answer:
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
Answer:
True
Explanation:
The process of photosynthesis converts light energy to stored chemical energy by converting carbon dioxide plus water into sugars plus released oxygen.
