Answer:
Cell of and integument
Explanation:
When flowering plants reproduce by sexual reproduction, they form seeds contained into fruits. The fruit is derived from the maturation of the flower's ovary (female part) after fertilization.
A mature seed contains three generations:
- a diploid embryo (the new sporophyte),
- The embryo is surrounded by haploid female gametophyte tissue that supplies nutrition
- All the above structure is in turn surrounded by the seed coat (diploid parental sporophyte tissue). The seed coat is produced by integument cells to protect the embryo during its development and before its can germinate. As it is produce by it parental plant, its ploidy level diploid.
In contrast, the generative nucleus and sperm cell are part of male gametophyte (pollen grain) and therefore haploids. Synergid cell is part of embryo sac, therefore belongs to female gametophyte and thus being haploid. Finally, cell of endosperm is usually derived from the fusion between a sperm cell and one of the two female gametes present within the embryo sac, thus being triploid.
Answer:
The cutaneous membrane is made of a simple columnar epithelium
Explanation:
Cutaneous membrane is the membrane of the skin. This membrane protects the skin from the physical and chemical damage.
Cutaneous membrane is present on skin and exposed to the external environment. This membrane is made of stratified squamous epithelium and keratinized and consist of the underlying layer of dermis. Hence, the membrane is not made upof simple columnar epithelium tissue.
Thus, the correct answer is option (3).
Answer:
A) 300
B) 3:1
C) 9 long yellow : 3 long green : 3 short yellow : 1 short green
Explanation:
Long stems (L_) are dominant to short stems (ll)
Yellow seeds (Y_) are dominant to green seeds (yy)
We interbred pea plants with long stems and yellow seeds (L_Y_), but they had a short green parent (llyy) that could have only produced <em>ly</em> gametes, so our plants are heterozygous <em>LlYy</em>.
C) We interbred them LlYy x LlYy. If the two genes are unlinked, this is a typical dihybrid cross and from Mendel's law of independent assortment we know that the offspring will have the following phenotypic ratios:
- 9/16 L_Y_ (Long, yellow)
- 3/16 L_yy (Long, green)
- 3/16 llY_ (short, yellow)
- 1/16 llyy (short, green)
A) 3/16 × 1600 = 300 plants will be long and green.
B)
9/16 + 3/16 = 12/16= 3/4 plants will be yellow;
3/16 + 1/16 = 4/16= 1/4 plants will be green.
The ratio will be 3 yellow : 1 green
Answer:
The alpha helices in the beta subunit are a ring shaped protein.
Explanation:
<em>Because the beta encircles DNA like a ring used gel filtration and radioactive beta subunit. Tipically beta and gamma complex are needed for fast and processive synthesis by polymerase III core. Some researchers realized that adding polymerase III core to the gel filtered isolated ³H-beta- DNA provide fast DNA synthesis typical of the polymerase III holoenzyme. Therefore the gamma complex is only needed to get the beta subunit onto the DNA, and is not required afterward.</em>
Answer:
Two adaptations of Darwin's Finches that helped them to survive are:
- Behavioral adaptations to use tools for foraging.
Explanation:
There are fourteen species of Darwin's finches that originated from a single species of ground dwelling seed eating finch.
These Finches occupied different niche in the Galapagos island and were widely studied by Darwin.
These finches are one of the best Examples of Adaptive radiation.
Studies state that during severe drought in Galapagos island most vegetation dried out and a few softer seeds were left.
These few seeds were quickly fed upon by the birds and only dry , hard seeds were left.
Only birds who had large and hard beaks could feed on these hard dry seeds.
To Ensure survival the Finches developed adaptations which resulted in hard and large beaks so that they can feed on those dried hard seed.
Some groups started feeding on insects and got their beaks adapted to capture and kill insects.
Second line of adaptation included changes in behaviour and cognitive intelligence where birds started using tools for foraging.
