Which space exploration vehicle has no crew and is used to collect data?

For this assignment you will develop a scientific model on a poster that illustrates the role of photosynthesis and cellular res

9966 [12]

Answer:

but you need to do this at home

Explanation:

8 0

3 years ago

A couple planning their family are aware that through the past three generations on the husband's side a substantial number of s

Nesterboy [21]

Answer:

a) There are lots of genes on chromosome 1 could be affected, and the gametes could be imbalanced (missing segments of DNA or whole chromosomes)

b) Roughly 50%

c) No. I would advise that the couple undergo preimplantation genetic diagnosis, so that a zygote carrying the normal copy of chromosome 1 could be selected.

Explanation:

Chromosome 1 is one of the largest and most gene rich chromosomes. An inversion that covers 70% of its length would cover lots of genes.

While an inversion on its own would not seem problematic (as all the genes on the chromosome are still there), when it comes to meiosis, the sister chromatids would not be able to correctly align, and crossing over would further complicate this. It could also lead to unbalanced gametes missing entire parts of the chromosome. Therefore, there are likely numerous genes that will be affected and messed up by the inversion.

This could explain the high incidence of past still births, as if lots of genes are affected, and non-functional, the pregnancy would be rendered non-viable, or highly deleterious causing premature death.

b) There is a 50% chance of a child inheriting the defective copy of chromosome 1 (and 50% of a chance of them inheriting the normal chromosome 1. Therefore, there is likely a 50% chance that future offspring would be affected by defects

c) No. I would advise that the couple undergo preimplantation genetic diagnosis. In this, the couple undergoes in vitro fertilization (IVF). When embryos are produced through IVF, they can then be tested for the presence of the abnormal chromosome. Embryos will only be implanted into the mother if the normal chromosome 1 is present.

6 0

3 years ago

Pervez peeled an apple and kept it on a plate. After half an hour, he found that it looked slightly brown. Why did this probably

vova2212 [387]

It was exposed to oxygen. This is called oxidation and it's a chemical reaction, meaning it can't be reversed.

5 0

4 years ago

The restriction endonuclease ecori cleaves the dna sequence 5'-gaattc-3' in such a way as to leave a 5' overhang, which is often

qaws [65]

The restriction endonuclease EcoRI cleaves the DNA sequence 5'-GAATTC-3' in such a way as to leave a 5' overhang, which is often referred to as a "sticky end". To 5' overhang with the complementary sequence this sticky end adhere.

The palindrome EcoRI restriction site breaks DNA after G and creates sticky ends with AATT. G/corresponding AATTC's DNA sequence is CTTAA/G, where "/" designates the location of the peptide bond break.

When the ssDNA sequence 5'-GAATTC'-3 is recognised by the restriction endonuclease EcoRI, a single-strand cut is made between the G and A nucleotides.

At the ultimate end of double-stranded DNA, an overhang is single-stranded DNA. This can occur on either strand, and if it does, there will either be a 5' overhang on the 5' end of the strand or a 3' overhang on the 3' end of the strand.

To learn more about DNA.

brainly.com/question/316480

#SPJ4

8 0

2 years ago

Describe the vascular system of plants. Include brief descriptions of the characteristics and function of xylem and phloem.

solong [7]

Answer:

The vascular tissue of the plants distributes water and nutrients, which guarantees a constant growth. Each newly formed cell needs to become the corresponding cell type in vascular tissue.

Explanation:

Like animals, plants need water and nutrients. While animals use a circulatory and digestive system to obtain and distribute nutrients, plants use a vascular system. This system absorbs water, vitamins and minerals from the soil and then transmits energy in the form of carbohydrates to the roots. The main components of the vascular system are the xylem and the phloem.

<u>Xylem</u> is a complex tissue formed by several cell types. Its function is the conduction of water and minerals from the root to the leaves. Among the cells that form this complex tissue differ:

- Conductive cells or tracheal elements: they are dead elements at maturity, they serve for vertical conduction and support

- Vessel members are observed in Angiosperms, the largest plant group with the most recent evolution; They are short, wide cells with thick secondary walls, they differ from tracheids because they are perforated elements.

- Storage elements: parenchymal cells, thick walls, secondary, can present crystals and other cellular contents.

- Support elements: fibers in the Angiosperms and fibrotracheids in Gymnosperms, elements of intermediate characters between the fibers and the tracheids.

<u> Phloem</u> cells conduct food (photosynthesis produced by photosynthesis) from the leaves to the rest of the plant. They are living cells at maturity and in histological preparations colored with Astrablue take the color blue. Phloem cells are located outside the xylem.

The sieve elements of this tissue are: the sieve cells in the Gymnosperms and the members of sieve tubes with their respective accompanying cells in the Angiosperms. The accompanying cells retain their nuclei and control the neighboring sieve tubes. Dissolved food, such as sucrose, circulates through the screened areas that connect these cells to each other.

Being a complex tissue, it also has parenchymal cells for storage and fibers and sclereids as a support.

4 0

4 years ago