Answer:
a. True
b. True
c. False
d. True
e. False
f. False
g. True
Explanation:
The homeotic genes refer to evolutionarily conserved genes that modulate the development of different structures in organisms of the same groups (in this case, plants). Moreover, homeobox genes are genes that encode transcription factors involved in the regulation of development in eukaryotic organisms. The knotted1 (<em>kn1</em>) gene is a plant homeobox gene is a member of the <em>kn1</em> homeobox (<em>knox</em>) gene family, which is responsible for maintaining indeterminacy and preventing cellular differentiation. In maize, <em>kn1</em> plays a key role in maintaining the cells of the shoot apical meristem in an undifferentiated state, being mainly expressed in shoot meristems during postembryonic stages of shoot development. It has been observed that maize mutant plants where <em>kn1</em> is ectopically expressed (i.e., in tissues in which this gene is not normally expressed) exhibit proximal-distal patterning defects.
The human brain can be divided into three<span> main parts: the forebrain, midbrain, and hindbrain: 1/ The forebrain includes the several lobes of the cerebral cortex that control higher functions.</span>
23. The answer would be the third option.
24. The answer would be the second option.
Answer:
Meiosis and Genetic Variation.
Explanation:
When homologous chromosomes form pairs during prophase I of meiosis I, crossing-over can occur. Crossing-over is the exchange of genetic material between non-sister chromatids of homologous chromosomes. It results in new combinations of genes on each chromosome.
When cells divide during meiosis, homologous chromosomes are randomly distributed during anaphase I, separating and segregating independently of each other. This is called independent assortment. It results in gametes that have unique combinations of chromosomes.
In sexual reproduction, two gametes unite to produce an offspring. But which two of the millions of possible gametes will it be? This is likely to be a matter of chance. It is obviously another source of genetic variation in offspring. This is known as random fertilization.
