Cell - Egg Cell
Tissue - Muscle tissue
Organ - Lung
Organ system - Respiratory system
Organism - Dog
Eukaryotic cells all feature a nucleus, and their organelles are enclosed inside membranes.<span> They also have a plasma membrane, which is a layer of phospholipids that surrounds the whole cell, and they feature an internal cytoskeleton</span>
Answer:
Option B, The controls on cell growth and divisions can be turned on and off
Explanation:
There are signal proteins that control and regulate the cell growth and division process. For instance, mitogens help in removing the negative controls which would otherwise have blocked the cell cycle progression. Then there are growth factors that synthesize proteins and hence stimulate cell growth. Also there are some survival factors that suppress the apoptosis. Based on these three factors the cell division and growth can be turned on or off.
Hence, option B is correct
Answer:
Phenotypic ratio = 1 Red : 1 Pink
Explanation:
This phenomenon exhited by the gene coding for flower colour in four o'clock plants is called INCOMPLETE DOMINANCE i.e. the red flower allele (R) is not completely dominant over the white flower allele (r), hence, a third intermediate pink phenotype (Rr) is formed in an heterozygous state. The red and white flowers will only be expressed in a RR and rr genotypes respectively.
In a cross between a red-flowered 4 o'clock plant (RR) and a pink-flowered 4 o'clock plant (Rr), the gametes:
R and R will be produced by the red-flowered plant while gamete R and r will be produced by the pink-flowered plant. Using this gamete in a punnet square, one will have four possible offsprings in which two will be phenotypically red-flowered (RR) and two phenotypically pink-flowered (Rr). i.e. 2RR:2Rr
Hence, the phenotypic ratio is 1:1 Red to Pink flower
