food exchange systems were originally developed for people with ___

Purple is the dominant color in hedgehogs and yellow is recessive. Cross 2 heterozygous individuals with each other. What percen

elena55 [62]

Answer:

Purple is the dominant color in hedgehogs and yellow is recessive. Cross 2 heterozygous individuals with each other. What percentage of the offspring will carry the purple allele? one over four

5 0

3 years ago

Which cells are responsible for the movement of photosynthates through a plant?

jasenka [17]

Answer:

sieve-tube elements, companion cells

Explanation:

Sieve-tube elements and companion cells are responsible for the movement of photosynthes through a plant.

The sieve tube elements are shorter (almost organelle-free) living cells, placed end to end, forming the sieve tubes. Their transverse cell walls are called sieve plaques that make connections between cells and through openings called sieves establish the connection between the cytoplasm of adjacent cells. Each sieve is coated with calose (glucose polymer), which in winter can completely clog the vessel and then dissolve in spring. When infections occur or the vessel is parasitized, it can also be clogged with callose.

Companion cells are specialized parenchymal cells, which contain all the components that exist in living cells, including the nucleus, are the cells most closely linked to the sieved tube element. The Screened Tube Element and its companion cells are related in development, are derived from the same mother cell, and have several cytoplasmic connections to each other. Due to the many connections, the potential function of the companion cells is to release substances into the sieved tube element and, when the nucleus is absent, to include information molecules, proteins and ATP. When a screened element dies, its companion cells also die, which is a demonstration of this interdependence.

8 0

3 years ago

Contracts Slowly Striated Voluntary

hoa [83]

Answer:

student 1

Explanation:

The smooth muscles contract and fatigue slowly but are not striated and are innervated by involuntary nervous system. The cardiac muscles are uninucleate and striated. The skeletal muscles are innervated by the voluntary nervous system hence concerned with voluntary movement.

4 0

3 years ago

When a living organism dies, it stops taking in new carbon. Thus, as the radioactive carbon-14 decays, the ratio of carbon-12 to

Alexxandr [17]

Answer: The fossil is 11459 years old.

Explanation:

Half-life of carbon-14 = 5700 years

First we have to calculate the rate constant, we use the formula :

$k=\frac{0.693}{5700\text{years}}$

$k=1.21\times 10^{-4}\text{years}^{-1}$

Now we have to calculate the age of the sample:

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant = $1.21\times 10^{-4}\text{years}^{-1}
t = age of sample = ?
a = let initial amount of the reactant = 100 g
x = amount decayed = 75 g
a - x = amount left after decay process = 100 - 75 = 25 g Now put all the given values in above equation, we get
[tex]t==\frac{2.303}{1.21\times 10^{-4}}\log\frac{100}{25}$

$t=11459years$

The fossil is 11459 years old.

4 0

3 years ago

Where do the axons that enter the cortico-spinal tract originate? (The complete answer should include more than one of Brodmann’

torisob [31]

Answer:

<u>From the main motor cortex, Brodmann region 4 premotor areas and the primary somatosensory cortex .</u>

<u />

Explanation:

The corticospinal tract originates in many regions of the brain, including

the motor regions,
main somatosensory cortex
pre-motor regions

The corticospinal tract allows for voluntary control of motor functions.

30% of the neurons in the corticospinal regions are found in the primary motor cortex. 40% are split up in several regions; the parietal lobe, somatosensory cortex and the cingulate gyrus.

The axon is a tube enclosed in and insulated by the myelin sheath. It serves as a link to impulses for certain neurons that often comprise axon hillocks that are junctions between the axon and the cell body.

6 0

3 years ago

​food exchange systems were originally developed for people with ____.​

food exchange systems were originally developed for people with ____.