Explanation:
The classical cell theory was proposed by Theodor Schwann in 1839. There are three parts to this theory. The first part states that all organisms are made of cells. The second part states that cells are the basic units of life. These parts were based on a conclusion made by Schwann and Matthias Schleiden in 1838, after comparing their observations of plant and animal cells. The third part, which asserts that cells come from preexisting cells that have multiplied, was described by Rudolf Virchow in 1858, when he stated omnis cellula e cellula (all cells come from cells).
Since the formation of classical cell theory, technology has improved, allowing for more detailed observations that have led to new discoveries about cells. These findings led to the formation of the modern cell theory, which has three main additions: first, that DNA is passed between cells during cell division; second, that the cells of all organisms within a similar species are mostly the same, both structurally and chemically; and finally, that energy flow occurs within cells.
Heterozygous Red- Rr
Homozygous Red-- RR
Homozygous white-- rr
Monohybrid cross- Rr
Recessive allele- homozygous white i.e rr
Explanation:
Heterozygous have 2 different alleles of a gene as both Red and white alleles are present in the example Rr.
Homozygous: If the 2 alleles at a locus is same then they are homozygous, it can be dominant as RR or recessive as rr.
Recessive gene are the ones that can be masked by the dominant genes as red is dominant on white.
Monohybrid cross is the result of cross between the individual having either homologous dominant or recessive genes or genotype. The result is generally masking the recessive allele resulting in dominant phenotypic trait but the genotype changes.
From the example given in question:
A cross between dominant red as RR
and a cross between recessive white as rr
The punnet square shows:
r r
R Rr Rr
R Rr Rr
it can be seen that all progeny are red but genotype changed to heterozygous red as Rr
Hello. This question is incomplete. The full question is:
A tRNA anticodon is 5' GAA 3'.
Which one of the following codons is recognized by this tRNA?a) 5' UUC 3'b) 5' CTT 3'c) 5' CUU 3'd) 5' TTC 3'
Answer:
a) 5' UUC 3'
Explanation:
Anticodons are sequences of nitrogenous bases that establish complementarity with sequences of nitrogenous bases in a codon.
As you know, mRNA has the nitrogenous bases Adenine (A), cytosine (C), guanine (G) and uracil (U). In this system, guanine is supplemented with cytosine and adenine is supplemented with uracil.
These bass are organized into codons, which are a set formed by 3 of these bases.
The tRNA has the same bases, but its codons must recognize and complement the codons of the mRNA, being then called Anticodons.
In this case, if a tRNA has the anticodon 5 'GAA 3', it must bind to codons 5 'UUC 3' in the mRNA.
Answer:
Red blood cells are the type of cells which are responsible for the transportation of oxygen and carbon in the body.
White blood cells are the type of cells which are responsible for the protection of body against pathogens such as bacteria and viruses etc
Platelets are those cells which helps in blood cloting after injury.
Plasma is a liquid medium in which nutrients, water and blood cells are present. Its main function is to transport nutrients to the body where it is required.
The brain which, along with the spinal cord gathers informationand responds to changes in the environment.
