1. breeding of individuals that have genes for two different characteristics:
DIHYBRID CROSS.
We call it a dihybrid cross when we are considering a cross between two different traits.
"di" means having two traits involved (for example, trait A and trait B), the "hybrid" means that each trait will have two different alleles (for gene A: A or a; for gene B: B or b), one is dominant and the other is recessive.
2. a grid system used to predict possible combinations of genes due to random fertilization: PUNNETT SQUARE
The Punnett square is a grid system that helps us predict an outcome of a cross or a breeding experiment. We this, we can determine the probability of an offspring having a particular genotype.
This is very useful when we are considering more than one gene, making it less confusing.
3. a condition in which both alleles are dominant: CODOMINANCE
Tere are alleles that have the capacity of dominating at the same time, and when an organism is heterozygotic, both alleles are expressed.
For example, a white chicken(WW) crossed with a black chicken (BB): 100% of the offspring being WB. With this genotype, they have black feathers and white feathers. It's not a blend of colors, but a case where both are expressing.
4. when more than two alternatives exist for a gene: MULTIPLE ALLELES
Mendel thought that only two possible alternatives could exist for a gene, but there are cases that have more than 3 possibilities. Some of those can be really popular in a population while others not so much.
This happens with rabbit's fur. They can be black, brown, grayish,
Himalayan patterning or white fur.
5.a condition in which neither pair of alleles is dominant or recessive, so the traits blend in the phenotype: INCOMPLETE DOMINANCE
Some alleles are not completely dominant, and when that's the case the phenotype of a heterozygous organism will be a mix between the phenotypes of its homozygous parents.
For example:
plant 1: RR -red
plant 2: rr-white
By crossing this plants we will obtain 100% of the offspring with a color mix: pink.(genotype: Rr)
Red and white are not completely dominating so it results in a blend of colors.
March and January would be the most similar
The answer is dams they protect against flooding
Answer:
In addition to biology, evidence drawn from many different disciplines, including chemistry, geology, and mathematics, supports models of the origin of life on Earth. In order to determine when the first forms of life likely formed, the rate of radioactive decay can be used to determine the age of the oldest rocks (see optional problems C and D, below) exposed on Earth’s surface. These are found to be approximately 3.5 billion years old. The age of rocks can be correlated to fossils of the earliest forms of life. A. The graph compares times of divergence from the last common ancestor based on the fossil record with a "molecular time" constructed by comparing sequences of conserved proteins to determine a mutation rate (after Hedges and Kumar, Trends in Genetics, 2003). Explain how such a molecular clock could be refined to infer time or the evolution of prokaryotes. B. Using a molecular clock constructed from 32 conserved proteins, Hedges and colleagues (Battistuzzi et al., BMC Evol. Biol. 2004) estimated the times during which key biological processes evolved. A diagram based on their work is shown. Connect the time of the origin of life inferred from this diagram with the age of the oldest fossil stromatolites and the age of the oldest exposed rock to show how evidence from different scientific disciplines provides support for the concept of evolution. Evaluate the legitimacy of claims drawn from these different disciplines (biology, geology, and mathematics) regarding the origin of life on Earth. The oldest known rocks are exposed at three locations: Greenland, Australia, and Swaziland. The following application of mathematical methods provides essential evidence of the minimum age of Earth.
Explanation:
Answer:
Function of each male reproductive system-
They produce, maintain and transport sperm and semen . They discharge sperm into the female reproductive tract. They produce and secrete male sex hormones.
Function of each female reproductive system-
The ovaries produce the egg cells, called the ova or oocytes. The oocytes are then transported to the fallopian tube where fertilization by a sperm may occur.
